Apparently, the early version of the Edge of Tomorrow script had an even more time-bending third act prepared than we actually got. And it was also a much darker time jump than before.

Speaking with Film School Rejects, screenwriter Christopher McQuarrie described a scene he had originally written for the end of the film:

When Tom loses the power, and they go to Paris, and Tom is preparing the team as they go into Paris where he's telling them the rules of the movie, he tells the team everything the audience knows. Basically, he told them: 'Kill as many Mimics as you want, but do not kill an Alpha. If you kill an alpha we'll be right back here having this conversation, and we won't even know it. The enemy will know we're coming and they'll kill us all.' When they get to Paris there's the classic horror movie scene where one of them gets separated from the group, and he gets attacked by an Alpha and kills it. As he kills it, you see the Omega reset the day and you see the point-of-view of the villain. We cut to the plane and hear the same speech all over again. This time when he gets to the line, 'You can bet they'll have a plan to kill us all,' the ship gets hit. As the audience, you realize the enemy knows they're coming. The problem was you were so exhausted by the time you got to that point.

That was one time twist too many, according to McQuarrie. Read more about the ending they did end up going with and why at Film School Rejects.